Load hoisting device



Feb. 18, 1947. c. rs.y PIERCE LOAD HOISTING DEVICE Filed Nov. 7, 1944. 2 Sheets-Sheet l Feb la, im?. C. E. PIERCE www LOAD HOI STING DEVICE Filed Nov. 7,' 1944 2 sheets-sheet, 2

Invenr: Cm! -6- Pm .Patented Feb. 18, Y1947 UNITED ySTATES anat? ATENT OFFICE The present invention relates generally to improvements in cranes and, as illustrated herein, consists more particularly in an improved load hoisting device particularly adapted for use on automotive trucks and the like.

Swinging cranes which are carried on a truck or wagon for hoisting a load from the ground and onto the body of the truck or wagon have not heretofore come into common use since the prior constructions have not been entirely satisfactory. The hoisting elements inmany cases have been cumbersome and have taken up too much space on the body of the .truck or wagon. It has also been difficult to provide controls for operating the crane or hoist which could be located within convenient reach oi the operator. In many cases, also, the hoist or Icrane was so expensive that it proved to be more economical for the truck or wagon owner to load the vehicle by hand. Furthermore, in many hoisting devices the arc through which the crane arm could travel Was limited and hence it was not always possible to place the end of the crane in the proper position to receive a load or to discharge a load.

One object of the present invention, accordingly, is to provide a simple, inexpensive crane or hoist by the use of which the above mentioned difficulties will be overcome. To this end and, as illustrated, the crane comprises a vertical member or mast to which is rigidly secured a hori- Zontal arm which is constructed and arranged to form a cylinder for a pneumatic piston and which arm takes the weight of the load. The vertical member or mast is supported in a vertical standard fastened to the body of a truck and, as illustrated, the crane is readily removable from the standard.

With the above and other objects and features in view, the invention will now be described with particular reference to the accompanying drawings which illustrate one embodiment of the invention and in which:

Fig. 1 is a sectional view of a crane or hoist illustrating a preferred embodiment of the present invention;

Fig. 2 is a plan View of a portion of the swinging arm illustrating the relation between the movable sheave and the slot in the swing arm through which the support for the movable sheave projects;

Fig. 3 is a detailed sectional View illustrating the construction of the cylinder end of the horizontal swinging arm;

Fig. 4 is a plan view of the crane 'applied to an automotive truck; and

2 Claims. (Cl. 212-31) Fig. 5 is a view in rear elevation of the truck shown in Fig. 4.

The present yinvention is illustrated in Figs. 4 and 5 as applied to an automotive truck of usual construction having a platform i2 and a headboard EG which is rigidly secured to the platform l2 by usual braces, not shown, so that it forms a rigid and substantial vertical'wall -to which the present hoisting device may be secured. The truck is provided with the usual racks l which form the sides of the truck body and are readily removable to permit loading of the truck.

The illustrated crane or hoist is rotatably mounted in a hollow tubular standard 20 having a iiat plate 22 welded to its lower end. The plate 22 is provided with a plurality of holes for receiving the bolts 24 to secure the standard or base 2i! rmly to the platform l2 closely adjacent the headboard ifi. The upper end of the standard `Z is rigidly held in place by a U-bolt 25 extending through the headboard Ell. In the present construction, which is designed particularly for loading potato barrels which weigh approximately 235 pounds, the standard 2E! is formed of a 31/2 pipe which has a wall approximately li" thick. This size of pipe has been found to be 4suitable for this particular purpose but it is evident that the size of the standard 2S and the thickness of the wall thereof may readily be varied depending upon the weight of the load to be'handled.

The crane or hoist proper Vis provided with a vertical tubular member or mast 28 dimensioned to :tit into the standard 2li in such a manner that it rotates freely therein. The upper end of the mast 28 is cut away or shaped to receive an elongated cylindrical member 30 which is Welded near one end to the mast 28 and extends perpendicularly therefrom. The cylindrical member may conveniently `be formed of a 3 pipe having an outside diameter of 31/2. The inside of the cylinder 3d is lined with a smooth bore liner 32 which nts snugly into the pipe to form a cylinder in which a piston B reciprocates. The inner end of the cylinder 30 projects beyond the mast or vertical member 28 and is threaded to receive an internally threaded cap 36. A gasket 38 is interposed between the inner end of the cylinder 30 and the cap 35. The liner 32, which may be a copper tube, terminates short of the outer end of the cylinder 30. A pipe or tube Ml having a 3 outside diameter is joined to the end of the cylinder 3B adjacent to the end of the liner 32. The tube 40 is welded to the cylinder 30, thus forming a rigid integral construction 3 which serves to maintain the liner 32 in position.

The tube 4B is provided with a slot 42 which is substantially equal in length to the length of travel of the piston 34. The piston 34 is provided with a piston rod 54 which is bolted at one end to the piston 34 in the usual manner and at its other end is provided with a sliding hea-d 46 which ts into the inside of the tube 49. Adjacent the head 45 is provided a narrow support 48 rigidly secured to the outer end of the piston rod 44 by fastenings such as bolts orgivets 5c and extending outwardly through the slot 132 in the walls of the tube 4S. The support 4S at its upper end carries a sheave 52 about which a cable v54 is rove. The cylinder S0 has secured thereto in alignment with the slot l2 in the tube or cylinder 43 a support 5S which is secured to the tube 3), preferably by welding, The support 56 extends substantially above a sheave 58 which is rotatably mounted on the support and forms an anchorage for one end ci the cable 54. The cable 54 passes toward the free end of the horizontal arm comprising the cylinders 3E! and 4S and about the aforesaid sheave 52 and returns toward the supported end of the horizontal arm and about the sheave 58 and then passes toward the free end of the horizontal arm provided with a sheave 65 which is supported on a pivot pin 62 passing through suitable openings in the tube Eil. By means of the construction just above outlined, the piston 34 may be moved toward the right as Viewed in Fig. l by compressed air supplied in a manner which will later be described, a distance of approximately two feet while the end of the cable 54 will be raised twice that distance or approximately four feet. The lower endY of the cable 54 is provided with a grapple, not shown, which is designed to engage and grip, for instance, a barrel lled with potatoes.

The cylinder or tube 32 is provided vwith compressed air from anysuitable source through a flexible tube 84 which is connected to a valve 6B having a control handle 68. The valve 65 is connected to a second valve 70 by a short tube 12. Thus when the valve 65 is opened compressed air is free to pass through the valve S6 and into the valve 1G. The valve TS is provided with a control handle i4 and with a vent 16 which discharges into the open air. The valve '.'0 is connected to the cylinder 32 by a tube 13 connected to a i'itting having an opening therein leading into the interior of the tube 32.

When the valve 66 is opened by the operator to permit compressed air to fiowthrough the valve 'l0 and the tube 18, the piston Se and the movable sheave 52 will be forced to the right as viewed in Fig. l, thus raising the lower end of the cable 54 as described above. When the cable has been raised the desired amount, the valve handle 68 is closed thus maintaining the cable 54 and its supported load in position and the horizontal arm comprising the cylinders 35 and 4 may be swung into any desired position over the platform l2 of the truck and the load may be deposited wherever desired within the radius ofthe horizontal load-carrying arm.

When it is desired to lower the end of the cable 54 and the grapple and load thereon, the handle 14 of the valve 'i0 is turned to such a position that the cylinder will vent through the opening 'ZB in the valve l'. The weight of the load on the cable will be sulcient to cause `the piston 34 and the piston rod 44 and the parts carried thereby to movertoward the left. When the load haetten dropped4 the piston may be re-v turned to its original position with the piston bearing substantially against the end cap 3S by merely pulling downwardly on the cable.

From the above, it will be noted that the construction is simple and is formed with a minimum number of movable parts and that the controls or valves @t and 'lil are located in a position close to the cab of the truck in such a manner that they are at all times within easy reach of the operator. Furthermore; the horizontal arm comprising the cylinders 30 and lll is sufliciently rigid .to support and hoist the desired load and also to provide a cylinder in which the piston 34 and its associated parts may reciprocate.

In one aspect, accordingly, my invention comprises a hoisting device in which la tubular horizontal movable arm is utilized for the two functions of supporting and carrying the load, and also to supply a cylinder for fluid pressure operating means. 1

While the piston 34 has been described as moving a distance of approximately 2 feet in its cylinder and as raising the hoisting end of the cable 5d to a distance of approximately Il feet, it will be understood that this speciiic description refers only to the particular embodiment of the invention shown herein for illustrative purposes and that it is well within the scope of the present invention to provide for a greater or lesser travel of the piston and a correspondingly greater or lesser movement of the hoisting` cable. It is also contemplated that wherever a greater ratio of movement is required between movement of the piston and the hoisting cable, double sheaves may be utilized in place of the single sheaves shown in the drawings.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: n

l. A load hoisting device comprising a vertically disposed tubular mast, a horizontally disposed tubular arm rigidly secured adjacent one end to the upper end of said mast, means for rotatably supporting the mast and its arm, said arm containing a uid pressure cylinder within its inner end and having a longitudinal slot extending outwardly beyond said cylinder and toward its outer free end, a piston slidable in said cylinder having a rod movable in said tubular arm and having a support extending outwardly through the slot therein, a sheave carried by said support and movable with the piston above said arm, stationarily mounted sheaves carried by the outer end and by the inner end portion respectively of said arm, a hoisting cable rove about the said last named sheaves and thesheave carried by the piston rod, and means for supplying a fluid pressure medium to said cylinder.

2. A load hoisting device comprising a vertically disposed tubular mast, a horizontally disposed tubular arm extending across the top of the mast and being closed at one end, said arm being rigidly secured adjacent to its closed end to the upper end of said mast, a base for rotatably'supporting the mast and its arm, said arm containing a iiuid pressure cylinder within its inner end and having a longitudinal slot extending outwardly beyond said cylinder and toward its outer free end, a piston slidable in said cylinder having a rod movable in said tubular arm and having a support extending outwardly through the slot therein, a sheave carried by said support and movable with the piston outside said arm, sta- .tionarily mounted sheaves carried' by. the outerend and by the inner end portion respectively of said arm, a hoisting cable rove about said last named sheave and the sheave carried by the piston rod, and compressed air connections leading to the closed end of said tubular arm.

CECIL E. PIERCE.

REFERENCES CITED The following references are of record in the le of this patent:

Number Anderson Aug. 7, 1900 

